TK-421 was the identification of the unfortunate Stormtrooper in Star Wars (and the only named Stormtrooper in the Star Wars movies) whose uniform was stolen by Luke and Han after they ambushed the scanning crew. The Stormtrooper disappeared from guarding the Millennium Falcon to supposedly assist the scanning crew, thus the line by Sub-Lieutenant Pol Treidum, Gantry Officer of Docking Bay 327, "TK-421, why aren't you at your post?" So in case any of you didn't know.